package com.tssm.core.util;
 import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

 

 /** 

  * 字符串工具集合 

  * @author xulong 

  */ 

 public class Encrypt { 

 private static final String PASSWORD_CRYPT_KEY = "__jDlog_"; 

 private final static String DES = "DES"; 

 

 /** 

  * 加密 

  * @param src 数据源 

  * @param key 密钥，长度必须是8的倍数 

  * @return  返回加密后的数据 

  * @throws Exception 

  */ 

 public static byte[] encrypt(byte[] src, byte[] key)throws Exception { 

         //DES算法要求有一个可信任的随机数源 

     SecureRandom sr = new SecureRandom(); 

     // 从原始密匙数据创建DESKeySpec对象 

     DESKeySpec dks = new DESKeySpec(key); 

     // 创建一个密匙工厂，然后用它把DESKeySpec转换成 

     // 一个SecretKey对象 

     SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES); 

     SecretKey securekey = keyFactory.generateSecret(dks); 

     // Cipher对象实际完成加密操作 

     Cipher cipher = Cipher.getInstance(DES); 

     // 用密匙初始化Cipher对象 

     cipher.init(Cipher.ENCRYPT_MODE, securekey, sr); 

     // 现在，获取数据并加密 

     // 正式执行加密操作 

         return cipher.doFinal(src); 

      } 

 

      /** 

  * 解密 

  * @param src 数据源 

  * @param key 密钥，长度必须是8的倍数 

  * @return   返回解密后的原始数据 

  * @throws Exception 

  */ 

  public static byte[] decrypt(byte[] src, byte[] key)throws Exception { 

     // DES算法要求有一个可信任的随机数源 

     SecureRandom sr = new SecureRandom(); 

     // 从原始密匙数据创建一个DESKeySpec对象 

     DESKeySpec dks = new DESKeySpec(key); 

     // 创建一个密匙工厂，然后用它把DESKeySpec对象转换成 

     // 一个SecretKey对象 

     SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES); 

     SecretKey securekey = keyFactory.generateSecret(dks); 

     // Cipher对象实际完成解密操作 

     Cipher cipher = Cipher.getInstance(DES); 

     // 用密匙初始化Cipher对象 

     cipher.init(Cipher.DECRYPT_MODE, securekey, sr); 

     // 现在，获取数据并解密 

     // 正式执行解密操作 

         return cipher.doFinal(src); 

      } 

   /** 

* 密码解密 

* @param data 

* @return 

* @throws Exception 

*/ 

   public final static String decrypt(String data){ 

      try { 

       return new String(decrypt(hex2byte(data.getBytes()),

          PASSWORD_CRYPT_KEY.getBytes())); 

     }catch(Exception e) { 

     } 

     return null; 

   } 

   /** 

* 密码加密 

* @param password 

* @return 

* @throws Exception 

*/ 

   public final static String encrypt(String password){ 

     try { 

       return byte2hex(encrypt(password.getBytes(),PASSWORD_CRYPT_KEY.getBytes()));
     }catch(Exception e) { 

     } 

     return null; 

   } 
   /**
	 * 对字符串转码
	 * 
	 * @param str
	 *            字符串
	 * @return
	 */
	public static String enStr(String str) {
		try {
			str = encrypt(URLEncoder.encode(str, "UTF-8"));
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return str;
	}

 /** 

  * 二行制转字符串 

  * @param b 

  * @return 

  */ 

   public static String byte2hex(byte[] b) { 

     String hs = ""; 

     String stmp = ""; 

     for (int n = 0; n < b.length; n++) { 

         stmp = (java.lang.Integer.toHexString(b[n] & 0XFF)); 

         if (stmp.length() == 1) 

             hs = hs + "0" + stmp; 

             else 

                 hs = hs + stmp; 

         } 

         return hs.toUpperCase(); 

    } 

    

   public static byte[] hex2byte(byte[] b) { 

     if((b.length%2)!=0) 

        throw new IllegalArgumentException("长度不是偶数"); 

     byte[] b2 = new byte[b.length/2]; 

     for (int n = 0; n < b.length; n+=2) { 

       String item = new String(b,n,2); 

       b2[n/2] = (byte)Integer.parseInt(item,16); 

     } 

     return b2; 
   }
   
 }
